The present invention relates to a method and device for controlling the concentration of ink in an ink-jet printer or the like.
There have been proposed various methods and devices for controlling the concentration of ink in ink-jet printers or the like. For instance, a diluent is added to the ink recirculation system when the concentration measured in terms of a number of ink drops dropping from a tube per unit time interval or a resistance of ink shows that the ink concentration is higher than a predetermined value. However, the above-described ink concentration measurements are adversely affected by the ambient temperature.
According to another prior art method, the concentration or viscosity is measured by detecting the flow rate of ink emitted from a dummy nozzle, but this method is also adversely affected by the ambient temperature.